Sepehr Sanaye, Navid Khakpaay, Daryoosh Borzuei
An innovative combination of optimization and energy management strategies for determining optimal equipment sizing and operational schedules of integrated cooling, heating and power systems incorporating ice thermal energy storage is proposed. Ice-based thermal energy storage offers significant potential for peak load shifting and cost reduction in buildings with continuous cooling demands. The investigated system employs gas engines combined with absorption and vapor compression chillers, where ice thermal energy storage operates in partial mode with charging during off-peak hours and discharging during on-peak periods. A dimensionless cooling capacity ratio was defined to distribute cooling loads optimally between absorption and compression refrigeration systems through the coupled optimization framework. Total system exergy efficiency and relative annual benefit were selected as dual objective functions, with nine decision variables optimized using genetic algorithm across four energy management strategies: Following Electrical Load, Following Thermal Load, Following Hybrid Load, and Minimum Distance Determination. Application to a residential complex demonstrated that integrating ice thermal energy storage with Following Thermal Load strategy achieved optimal performance, yielding maximum exergy efficiency of 49.59% and relative annual benefit of 1.15 × 10^6 $/year. The ice storage system enabled 48% load shifting from on-peak to off-peak periods, reducing peak electrical demand by 32%. The optimized configuration selected two gas engines with 432 kW total capacity operating at partial loads. Compared to alternative strategies, the optimal configuration produced 1.9–12.7% lower emissions and consumed 32.6–87.9% less backup boiler fuel, demonstrating the critical role of ice thermal energy storage in enhancing both thermodynamic and economic performance of combined cooling, heating and power systems.